Guard attachment for sewing machines



April'll, 1939. M. M CANN GUARD ATTACHMENT FOR SEWING MACHINES Filed NOV. 4, 1937 3 Sheets-Sheet l gwvewfoz J Mcam 1 W sww April 11, 1939. M. M cANN GUARD ATTACHMENT FOR'SEW'ING MACHINES 5 Sheets-Shet 2 Filed Nov. 4, 1937 gwua/wtcw Miehael Me Can/n Wwweas Apjl 11, 1939. M. McCANN 2,154,246

GUARD ATTACHMENT FOR SEWING MACHINES Mckael Me Cdnn Patented Apr. 11, 1939 UNITED STATES GUARD ATTACHIWENT FOR. SEWING MACHINES Michael McCann, Ozone Park, N. Y., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application November 4, 1937, Serial No. 172,661

Claims.

This invention relates to a guard attachment for sewing machines, and is designed more particularly for machines adapted to sewing buttons and the like to a body material.

The primary object of the invention is the provision of a guard which is automatically thrown into its protecting position when the work-clamp is lowered, so that if through accident the needle or article being attached is broken the operator will be effectively protected against injury by the flying particles.

Another object of the invention is the provision of a guard for a sewing machine adapted to prevent injury to an operator's fingers by the machine needle.

A further object of the present invention is to provide a universal guard attachment of simple construction which is susceptible of application to various conventional sewing machines without necessitating material alterations of the machines.

The invention further relates to arrangements and combinations of parts which will be hereinafter more fully described, pointed out in the appended claims and illustrated in the accompanying drawings, in which:-

Fig. 1 is a side elevation of a button sewing machine showing the improved guard attachment applied thereto.

Fig. 2 is an enlarged front elevation of the sewing machine with several of its parts omitted, showing the guard in operative position.

Fig. 3 is an enlarged plan view, partly in section, taken substantially along line 3-3, Fig. 2.

Fig. 4 is a perspective view of the guard-depressing arm, illustrating clearly the manner in which said arm is mounted upon the usual workclamp lifting bar or presser-bar of the machine.

Fig. 5 represents an enlarged perspective view of a portion of a conventional tacking and barring sewing machine, showing the guard in its operative position.

Fig. 6 represents only a portion of Fig. 5, showing the guard in retracted position.

Referring more specifically to the drawings,

the invention is disclosed as embodied in a sewing machine having a frame comprising a Worksupporting arm I, standard 2, bracket-arm 3 and head 4. Mounted within the head 4, and actuated by the usual needle-bar actuating mechanism 5, shown in dotted lines, is a conventional reciprocatory needle-bar 6 which carries at its lower end a needle 1. The needle cooperates with a suitable looper mechanism (not shown) located within the work-supporting arm I, to perform the required sewing operation upon the work placed between the needle and the looper. In the sewing machine disclosed in Fig. 1, the work-supporting arm I supports a work-clamp 8 having presserjaws 9 adapted to hold a button or the like in correct position for attachment to the work by the stitch-forming mechanism.

The work-clamp 8 is similar in construction to the work-holder disclosed, for instance, in the U. S. patent to Moo-re, No. 1,978,351, Oct. 23, 1934, and includes an upper bar 10 fulcrumed at its rearward end in a block ll carried by the main lower bar 12. Manually operable means is pro vided for lifting the upper bar IU of the workclamp, in opposition to the leaf-spring member 13, thereby to break the thread after the stitching operation has been completed and to facilitate removal of the work-piece from the work-clamp. The means employed in the present case for lifting the work-presser comprises the usual liftingbar M which carries at its lower end a lateral extension l5 adapted to engage under the hooked upper end of the post 16 rising from the upper bar Ill. The lifting-bar I4 is caused to move vertically in the machine-head 4 under the action of a treadle-controlled lever 11 which is manually actuated at the end of the sewing operation.

As will be observed in Figs. 5 and 6, the workclamp disclosed therein and designated as 8 is of different construction than that disclosed in Fig. 1, the work-clamp 8' being essentially the same as the work-clamp disclosed in the U. S. patent to Barron, No. 1,151,535, dated Aug. 24, 1915. It is one of the purposes of Figs. 5 and 6 to illustrate that the guard attachment, which forms the subject of this invention, may be applied to different varieties of sewing machines with equal facility.

My improved guard attachment preferably comprises a rectangular sheet-metal frame I 8 fitted with a transparent glass plate 19 through which the area about the stitching point may be observed. The glass plate I9 is held in the rectangular frame I8 by the plate 20 which is secured to the frame by screws 21. Preferably formed on the upper end of the plate 20 is a rearwardly extending ear 22, which ear is pivotally attached, as by the shouldered screw 23, to the forward end of the spring-biased arm 24 fulcrumed at its rearward end upon the pivot-stud 25 which is threaded into a supporting member or arm 26. The forward end of the supporting member 26 is enlarged and is rigidly fastened by screws 21 to the lower end of the bracket-arm head 4.

To cause the lower edge of the guard frame 18 to be moved inwardly toward the bracket-arm head 4 as the guard moves into retracted position (see Fig. 6), thereby to produce more clearance in the vicinity of the stitching point to facilitate the introduction and the removal of work, an upwardly and rearwardly inclined round guiderod 28 is pivotally connected at its lower end by a screw 29 to the lower ear 3!] of the plate 20. The guide-rod 28 is slidingly fitted in spaced bearings provided in the lateral projections 3|, 32 formed on the supporting arm 26.

As clearly illustrated in Figs. 5 and 6, the guard is spring-biased upwardly into retracted position by the coil-spring 33 which surrounds the pivotstud 25. The guard is preferably maintained in operative position during the stitching operation by means of a laterally and upwardly projecting guard-depressing arm 34 secured t othe liftingbar M by the screw 35, as shown in Fig. 4. This arm 34 carries at its free end a stud 36 which overlies the arm 24 and depresses it, thereby shifting the guard into operative position against the lifting action of the coil-spring 33 when the work-clamp is lowered. To provide for variations in the position of the bracket-arm head 4 relative to the base I of the various machines upon which the guard may be used, the arm 34 is provided with a plurality of threaded apertures 31, whereby the stud 36 may be adjusted to properly position the guard.

It will be obvious from the above description that when the machine has completed its sewing operation the rearward end of the lever I1 is pulled downwardly, thereby to raise the workpresser and permit the coilspring 33 to raise the guard out of its operative position. After the work has been removed from the work-presser and new work introduced, the lever I! is released permitting the work-presser to be lowered and simultaneously therewith bringing the guard into operative position.

One of the chief advantages of my improved guard attachment is that it may be readily applied to various types of conventional sewing machines by merely providing the bracket-arm head with two additional threaded apertures. Furthermore, no particular movement of the operator is required to place the guard in position or out of position for this is done by the same manual movement that raises or lowers the workpresser, and is done whether or not the operator desires it.

While the embodiment of the present improvement herein shown and described is deemed preferable, it is evident that the device is susceptible of material modification from the present disclosure without departure from the scope of the invention.

Having thussct forth the nature of the invention what I claim herein is:--

1. In a sewing machine, a frame including a base and a bracket-arm terminating in a head, a work-presser secured upon said base, a liftingbar mounted for endwise movement in said head, a guard secured upon said head and movable into and out of operative position, and means including an arm carried by said lifting-bar for moving said guard into and out of operative position.

2. In a sewing machine, a frame including a base and a bracket-arm terminating in a head, a work-presser supported by said base, means for raising said work-presser, a guard movable into and out of protecting position, means including an arm carried by said work-presser raising means for moving said guard into and out of protecting position, and means connected to the guard and engaging a fixed portion of the sewing machine for tilting the guard inwardly toward said head when the guard moves out of protecting position.

3. A guard attachment for sewing machines comprising, a supporting member adapted to be secured upon a fixed portion of the sewing machine, an arm pivoted to said supporting member, a guard carried by said arm, means acting between said supporting member and said arm for moving said guard out of operative position, and guard-depressing means adapted to be secured upon a movable portion of the sewing machine for moving said guard into operative position.

4. The combination as set forth in claim 3, in which the guard-depressing means is made adjustable to adapt the guard to various conventional sewing machines.

5. A guard attachment for sewing machines comprising, a supporting member adapted to be secured upon a fixed portion of the sewing machine, an arm pivoted to said supporting member, a guard carried by said arm, means for moving said guard out of operative position, means adapted to be secured upon a movable portion of the sewing machine for moving said guard into operative position, and means constructed and arranged to tilt the guard inwardly when the latter is moved out of operative position.

6. A guard attachment for sewing machines comprising, a supporting member adapted to be secured upon a fixed portion of the sewing machine, an arm pivoted to said supporting member, a guard carried by said arm, means for moving said guard out of operative position, means adapted to be secured upon a movable portion of the sewing machine for moving said guard into operative position, and means including a rod connected to the guard and guided in a bearing for tilting the guard inwardly when the latter is moved out of operative position, thereby to increase the clearance in the vicinity of the stitching point.

7. A guard attachment as set forth in claim 6, in which the bearing which slidingly receives the guide-rod is provided on the supporting member of the guard attachment.

8. The combination in a sewing machine with a work-presser, and means including a liftingbar for raising and lowering said work-presser, of a guard shiftable into and out of operative position, means including an arm carried by said lifting-bar for moving said guard into and out of operative position, and means constructed and arranged to automatically tilt the guard inwardly when the latter is moved out of operative position.

9. The combination in a sewing machine with a work-presser, and means for raising and lowering said work-presser, of a guard movable into and out of operative position, means carried by said work-presser raising and lowering means for moving said guard into and out of operative position, and means including a guide-member slidingly engaging a fixed portion of the sewing machine for tilting the guard inwardly when the latter is moved out of operative position.

10. In a sewing machine, a work-presser, means including a lifting-bar for raising and lowering said work-presser, a guard movable into and out of protecting position, a pivoted arm supporting said guard, means for moving said guard out of protecting position, and means carried by said lifting-bar and engaging said pivoted arm for moving said guard into protecting position.

MICHAEL MoCANN. 

